MCP File System

Implementation Reference

• src/index.ts:96-104 (handler)

  The handler function that executes the create_directory tool: validates the path, creates directory recursively with fs.mkdir, and returns appropriate content response.

  async ({ path: dirPath }: { path: string }) => {
      try {
          const validPath = validatePath(dirPath);
          await fs.mkdir(validPath, { recursive: true });
          return { content: [{ type: 'text', text: `Directory created: ${dirPath}` }] };
      } catch (error: any) {
          return { content: [{ type: 'text', text: `Error creating directory: ${error.message}` }] };
      }
  }

• src/index.ts:95-95 (schema)

  Input schema for create_directory tool using Zod: path as string.

  { path: z.string().describe("Directory path to create") },

• src/index.ts:93-105 (registration)

  Registration of the create_directory tool on the MCP server.

  server.tool(
      "create_directory",
      { path: z.string().describe("Directory path to create") },
      async ({ path: dirPath }: { path: string }) => {
          try {
              const validPath = validatePath(dirPath);
              await fs.mkdir(validPath, { recursive: true });
              return { content: [{ type: 'text', text: `Directory created: ${dirPath}` }] };
          } catch (error: any) {
              return { content: [{ type: 'text', text: `Error creating directory: ${error.message}` }] };
          }
      }
  );

• src/index.ts:14-20 (helper)

  Shared helper function validatePath used in the handler to ensure the directory path is within allowed directories.

  function validatePath(filePath: string): string {
      const absolutePath = path.resolve(filePath);
      if (!allowedDirs.some(dir => absolutePath.startsWith(path.resolve(dir)))) {
          throw new Error(`Access denied: ${filePath} is not within allowed directories`);
      }
      return absolutePath;
  }